Entities with substantial printing demands typically use a production printer. A production printer is a high-speed printer used for volume printing (e.g., one hundred pages per minute or more). Production printers include continuous-forms printers that print on a web of print media stored on a large roll.
A production printer typically includes a localized print controller that controls the overall operation of the printer, and a print engine (sometimes referred to as an “imaging engine” or a “marking engine”). The print engine includes one or more printhead assemblies, with each assembly including a printhead controller and a printhead (or array of printheads). An individual printhead includes multiple (e.g., hundreds of) tiny nozzles that are operable to discharge ink as controlled by the printhead controller.
Production printers typically have limited memory capacities for storing print data. This may cause a problem when a printer receives a print job in the PDF format, because a printer cannot initiate printing for a PDF print job until the entire PDF file has been stored in memory at the printer. Specifically, printing for a PDF print job (that is, the act of physically marking “dots on a page”) cannot start until page tree information for the job is read by the printer, and the location of the page tree information for a PDF print job is defined at the end of the PDF file for the print job. This results in two problems for a production printer receiving a large PDF print job from a print server. First, since the entire PDF file must be loaded into memory at the printer before printing initiates, the printer is idle for the entire period in which it is receiving a print job. This means that for large print jobs, the print shop must wait for a long period of time (e.g., an hour) before the first page even starts printing. Second, if the PDF document is too large for the memory of the printer (e.g., 120,000 pages), the memory of the printer overflows before the entire job is loaded, meaning that printing for the job fails.